1. Field of the Invention
The present invention relates to a system and method for monitoring the use of hearing protection devices to be worn by a user within a monitoring area. The invention further relates to detectable hearing devices and to a method for detecting the position of such hearing device.
2. Description of Related Art
A large part of the population is exposed to hazardous noise from time to time. This can be at work, whilst traveling, during leisure activities or at home. The exposure can lead to permanent hearing loss, distract people's attention from other hazards or simply cause stress. In order to prevent both accidents and permanent hearing damage, hearing protection devices (HPDs) have been provided in many styles and over many years. It started with the earmuff which is still very relevant and addresses very noisy environments (e.g. airports, construction, shooting) or complex working/communication situations (e.g. fighter pilots). Over the years development of biocompatible soft materials has enabled soft earplugs in different styles and colors as well as recent development of “one fits many” standard semi-soft earplugs in silicon-rubber type materials. For severe situations even the combination of an earmuff and an “in-the-ear” HPD is required to achieve desired attenuation. The physical limitation of hearing protection based on ear worn devices is defined where bone-conduction (body acoustics) becomes dominant at around 40 dB attenuation.
A common disadvantage of the above mentioned HPD styles is wearing discomfort. In case of the earmuffs, they are large which creates difficulties in combination with other head worn gear and they “close off” the ear too much for most applications. The in-the-ear styles mentioned are devices made to fit “the average” ear in one way or the other. Either the fit is provided by softness of the material which leads to undefined device insertion and undefined attenuation, or the fit is provided by standard shaped structures intended to block off the ear canal. In both cases the flat distribution of the individual shape of the outer ear and the ear canal leads to bad fit, pressure points in the ear and undefined positioning of the device.
To address this wearing comfort issue, in-the-ear hearing aid technology has been applied making customized ear molds with passive acoustical filter. These are long lasting devices with good wearing comfort. However, this customization process is traditionally a very manual process creating varying results over time, low reproducibility and the quality is very operator skill dependent.
The fabrication of customized shells by use of rapid prototyping technology, primarily for hearing aids, is described, for example, in U.S. Pat. No. 6,533,062 B1 or U.S. 2003/0133583 A1.
As already mentioned, hearing protection devices to be worn at the outer ear of the user, i.e. ear muffs, or to be worn at least in part within the user's ear canal, i.e. earplugs, are widely known. Both active devices, i.e. hearing protection devices comprising a microphone, a signal processing unit and a speaker for achieving selective sound attenuation, and passive devices, i.e. hearing protection devices without microphones and speakers, are used in practice. Hearing protection in general is of particular interest in industrial environments in order to protect the workers from hearing damages. While powerful hearing protection devices are available for such industrial environments, they will obviously not protect the worker, if he forgets or refuses to wear them in noisy environments. Hence, for achieving full hearing protection, it is not only necessary to develop appropriate hearing protection devices, but to also monitor the use of hearing protection devices in noisy environments, i.e. it would be desirable to provide for a control or monitoring of hearing protection device wearing compliance.
It is one object of the present invention to provide for a method and system for monitoring whether hearing protection devices are worn by a user within areas in which the use of hearing protection devices is required.
It is a further object of the invention to provide for a hearing device which can be identified or detected in a simple manner.
It is yet a further object of the invention to provide for a method for detecting such hearing devices, for example if lost.